The goal of this project is to define the proteins and DNA sequences required for the replication of adenovirus DNA. We will concentrate on: (1) continud work aimed at characterizing the adenovirus coded proteins which have been purified from cell free replication extracts. (2) Further characterization of the DNA sequences within the inverted terminal repetition of adenovirus DNA for their role in initiation and termination of DNA synthesis. (3) Identification and characterization of the host cell proteins required for adenovirus DNA replication by purification and determination of their enzyme activities. Antibodies against these proteins will be made and used to obtain genomic clones and to examine the regulation of these genes during the cell cycle. (4) Use of the purified cell replication proteins in other cell free replication systems which we will develop, such as SV40 DNA replication.